Patients with schizophrenia show deficits on spatial frequency doubling.

There are pieces of evidence indicating that visual deficits in patients with schizophrenia can be attributed to a deficiency in the magnocellular portion of the early visual system. The main objective of this study was to investigate the neurological dysfunction of the magnocellular pathway in patients with schizophrenia using the frequency doubling technology perimetry (FDT). The FDT has been developed based on particular neural magnocellular characteristics and can examine the magnocellular dysfunction hypothesis in schizophrenia. Twenty patients with schizophrenia (12 males and 8 females) and 20 normal subjects (10 males and 10 females) participated in this study. The spatial frequency doubling task was presented via the Humphrey perimetry instrument in order to examine the magnocellular pathway of the participants. Patients with schizophrenia showed less visual field sensitivity than normal controls and their standardized age cohort in both eyes (p<0.001). The results indicated impaired visual field sensitivity deficits in patients with schizophrenia that can be attributed to a deficit in the magnocellular neural pathways. This Magnocellular pathway defect may provide a physiological base to explain some of the deficits caused by schizophrenia such as cognitive deficits.